Augmented reality is one of virtual realities of displaying one image by combining a real world view, as viewed by a user's eyes and a virtual world having additional information. That is, in the augmented reality, a realistic image, which a user views, overlaps a 3D virtual image through a computer graphic, so that a discrimination between a reality environment and the virtual image is ambiguous. In the augmented reality, a realistic environment is combined with a virtual environment, so that the user may view the realistic environment, thereby providing an improved sense of reality.
Recently, a head-up display (HUD) projecting a current speed of a vehicle, residual fuel quantity, road guide information of a navigation device, and the like on a windshield glass part at a front side of a driver by a graphic image by using augmented reality has been developed. In particularly, a function of displaying a position and a distance of an object, for example, natural scenery, a road or a construction structure, a vehicle, and a pedestrian, in an actual space at a front side of the windshield glass through the HUD has been developed.
A distance between an object and a vehicle in the actual space may be recognized by transmitting radio waves or ultrasonic waves through a radar or a lidar and measuring a period of time in which the radio waves or the ultrasonic waves are reflected and returned from the vehicle.
In general, in a case where a front vehicle drives a curved road, the front vehicle is viewed as if the vehicle drives the curved road by moving in parallel at a predetermined distance in a transverse direction compared to a corresponding vehicle. However, the radar has a distance error of about 1 m in the transverse direction, so that when the augmented reality generates a position of the front vehicle by a graphic image, a large error between the actual position of the front vehicle and the graphic image is generated.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.